Instant Payment Notification (IPN) is PayPal's message service that sends a notification when a transaction takes place or when the status of a transaction changes. Once IPN is integrated, sellers can automate their back office as they receive updates on transactions that do not immediately complete.

IPN can send notifications for these transactions and status changes:

• Instant payments, including Express Checkout
• Pending, completed, or denied status payments
• Recurring payments and subscriptions
• Authorizations
• Disputes, chargebacks, reversals, and refunds

You can also view notifications on PayPal’s IPN History page and resend them if you need to.

As PayPal’s interface for handling purchase confirmation and server-to-server communications, IPN can also be used to manage and customize a variety of APIs and communications, including:

• Customize your website's response to customer purchases in seconds
• Track customers via IPN "pass-through" variables
• Notify sellers who deal mostly in software downloads and other digital, online goods
• Track affiliate sales and commissions
• Store transaction information in your own database

For more about IPN:

• Instant Payment Notification Guide (PDF)